MONDAY, Nov. 27, 2017 (HealthDay News) -- The main proponent of a controversial treatment for multiple sclerosis now has declared the therapy to be worthless.

For nearly a decade, Italian researcher Dr. Paolo Zamboni investigated inadequate blood flow as a potential cause of MS and has promoted reopening the veins that serve the central nervous system as a possible means of treating the progressive neural disease.

But his latest clinical trial has convinced Zamboni that the treatment simply doesn't work.

"The procedure cannot be recommended for treatment of patients with MS," Zamboni and his colleagues concluded in their paper on the clinical trial, published online recently in JAMA Neurology. "No further double-blinded clinical studies are needed."

In 2009, Zamboni reported that he'd found an association between multiple sclerosis and what he called chronic cerebrospinal venous insufficiency (CCSVI). That refers to compromised blood flow in the veins that drain the brain and spine.

No one yet knows exactly what causes multiple sclerosis so any evidence of a potential cause draws a lot of attention. In MS, the fatty sheath that surrounds and protects nerve fibers begins to break down under attack from the immune system.

In a statement responding to the study, the National Multiple Sclerosis Society said: "There is an urgent need for therapies that can stop disease activity and progression for everyone living with multiple sclerosis. Since Dr. Zamboni published his original theory about MS and CCSVI, the Society and other MS organizations and government agencies in many parts of the world invested in research to understand the proposed link between MS and CCSVI."

Zamboni followed his initial discovery with a small trial aimed at treating MS by reopening those veins using angioplasty, a procedure in which a balloon is inflated inside a blood vessel to flatten any possible obstructions to blood flow. The medical name for the procedure is venous percutaneous transluminal angioplasty (venous PTA).

The results were promising enough that Zamboni embarked on a full-scale randomized clinical trial, called "Brave Dreams," to test the therapy's effectiveness. Zamboni is director of the Vascular Diseases Center at the University of Ferrara in Italy.

"A number of neurologists and scientists expressed the opinion that the decision to conduct a trial on CCSVI in the absence of valid scientific evidence was unethical and a waste of resources," the researchers wrote in the newly published study.

"However, we believe that the best way to provide useful information to patients (and regulatory authorities) on the benefit and safety of venous PTA was to conduct a randomized trial ... that assessed outcomes directly relevant to patients," Zamboni's team added.

The research team tested the procedure on 76 people with MS, with another 39 undergoing a sham procedure to serve as the study's control group.

People given the treatment did not experience any improved function within a year of follow-up, however. Their MS also continued to progress, with the therapy doing nothing to significantly reduce the appearance of new brain lesions.

"So far," the National Multiple Sclerosis Society said in its statement, "the most thorough studies have not shown an association between CCSVI and MS. Now, two controlled clinical trials -- including the Brave Dreams study led by Dr. Zamboni -- have reported use of angioplasty to treat CCSVI did not provide a clear benefit for MS."

In an accompanying editorial, a group of neurologists and neuroscientists praised Zamboni for openly acknowledging that the procedure he championed had failed to show results.

"Zamboni et al should be applauded for their clear-eyed evaluation of their earlier theory in a rigorous and definitive fashion," Dr. Ari Green, of the University of California,
San Francisco, and colleagues wrote. "It is difficult to refute one's own prior findings, but the authors have used the right methods to test the CCSVI theory and have yielded an unequivocal result."

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about multiple sclerosis.